diff options
author | David Woodhouse <dwmw2@infradead.org> | 2008-02-03 18:29:41 +1100 |
---|---|---|
committer | David Woodhouse <dwmw2@infradead.org> | 2008-02-03 18:30:32 +1100 |
commit | c1f3ee120bb61045b1c0a3ead620d1d65af47130 (patch) | |
tree | 908430bf2b47fe8e96ac623ae7ab6dd5698d0938 /kernel/module.c | |
parent | e619a75ff6201b567a539e787aa9af9bc63a3187 (diff) | |
parent | 9135f1901ee6449dfe338adf6e40e9c2025b8150 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Diffstat (limited to 'kernel/module.c')
-rw-r--r-- | kernel/module.c | 294 |
1 files changed, 134 insertions, 160 deletions
diff --git a/kernel/module.c b/kernel/module.c index 3202c995007..bd60278ee70 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -47,8 +47,6 @@ #include <asm/cacheflush.h> #include <linux/license.h> -extern int module_sysfs_initialized; - #if 0 #define DEBUGP printk #else @@ -67,6 +65,9 @@ extern int module_sysfs_initialized; static DEFINE_MUTEX(module_mutex); static LIST_HEAD(modules); +/* Waiting for a module to finish initializing? */ +static DECLARE_WAIT_QUEUE_HEAD(module_wq); + static BLOCKING_NOTIFIER_HEAD(module_notify_list); int register_module_notifier(struct notifier_block * nb) @@ -81,12 +82,16 @@ int unregister_module_notifier(struct notifier_block * nb) } EXPORT_SYMBOL(unregister_module_notifier); -/* We require a truly strong try_module_get() */ +/* We require a truly strong try_module_get(): 0 means failure due to + ongoing or failed initialization etc. */ static inline int strong_try_module_get(struct module *mod) { if (mod && mod->state == MODULE_STATE_COMING) + return -EBUSY; + if (try_module_get(mod)) return 0; - return try_module_get(mod); + else + return -ENOENT; } static inline void add_taint_module(struct module *mod, unsigned flag) @@ -425,6 +430,14 @@ static unsigned int find_pcpusec(Elf_Ehdr *hdr, return find_sec(hdr, sechdrs, secstrings, ".data.percpu"); } +static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size) +{ + int cpu; + + for_each_possible_cpu(cpu) + memcpy(pcpudest + per_cpu_offset(cpu), from, size); +} + static int percpu_modinit(void) { pcpu_num_used = 2; @@ -497,6 +510,8 @@ static struct module_attribute modinfo_##field = { \ MODINFO_ATTR(version); MODINFO_ATTR(srcversion); +static char last_unloaded_module[MODULE_NAME_LEN+1]; + #ifdef CONFIG_MODULE_UNLOAD /* Init the unload section of the module. */ static void module_unload_init(struct module *mod) @@ -538,11 +553,21 @@ static int already_uses(struct module *a, struct module *b) static int use_module(struct module *a, struct module *b) { struct module_use *use; - int no_warn; + int no_warn, err; if (b == NULL || already_uses(a, b)) return 1; - if (!strong_try_module_get(b)) + /* If we're interrupted or time out, we fail. */ + if (wait_event_interruptible_timeout( + module_wq, (err = strong_try_module_get(b)) != -EBUSY, + 30 * HZ) <= 0) { + printk("%s: gave up waiting for init of module %s.\n", + a->name, b->name); + return 0; + } + + /* If strong_try_module_get() returned a different error, we fail. */ + if (err) return 0; DEBUGP("Allocating new usage for %s.\n", a->name); @@ -720,6 +745,8 @@ sys_delete_module(const char __user *name_user, unsigned int flags) mod->exit(); mutex_lock(&module_mutex); } + /* Store the name of the last unloaded module for diagnostic purposes */ + strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); free_module(mod); out: @@ -813,7 +840,7 @@ static inline void module_unload_free(struct module *mod) static inline int use_module(struct module *a, struct module *b) { - return strong_try_module_get(b); + return strong_try_module_get(b) == 0; } static inline void module_unload_init(struct module *mod) @@ -952,7 +979,8 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs, ret = __find_symbol(name, &owner, &crc, !(mod->taints & TAINT_PROPRIETARY_MODULE)); if (ret) { - /* use_module can fail due to OOM, or module unloading */ + /* use_module can fail due to OOM, + or module initialization or unloading */ if (!check_version(sechdrs, versindex, name, mod, crc) || !use_module(mod, owner)) ret = 0; @@ -1120,7 +1148,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect, ++loaded; } - notes_attrs->dir = kobject_add_dir(&mod->mkobj.kobj, "notes"); + notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); if (!notes_attrs->dir) goto out; @@ -1210,6 +1238,7 @@ void module_remove_modinfo_attrs(struct module *mod) int mod_sysfs_init(struct module *mod) { int err; + struct kobject *kobj; if (!module_sysfs_initialized) { printk(KERN_ERR "%s: module sysfs not initialized\n", @@ -1217,15 +1246,25 @@ int mod_sysfs_init(struct module *mod) err = -EINVAL; goto out; } - memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); - err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name); - if (err) + + kobj = kset_find_obj(module_kset, mod->name); + if (kobj) { + printk(KERN_ERR "%s: module is already loaded\n", mod->name); + kobject_put(kobj); + err = -EINVAL; goto out; - kobj_set_kset_s(&mod->mkobj, module_subsys); + } + mod->mkobj.mod = mod; - kobject_init(&mod->mkobj.kobj); + memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); + mod->mkobj.kobj.kset = module_kset; + err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, + "%s", mod->name); + if (err) + kobject_put(&mod->mkobj.kobj); + /* delay uevent until full sysfs population */ out: return err; } @@ -1236,12 +1275,7 @@ int mod_sysfs_setup(struct module *mod, { int err; - /* delay uevent until full sysfs population */ - err = kobject_add(&mod->mkobj.kobj); - if (err) - goto out; - - mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders"); + mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); if (!mod->holders_dir) { err = -ENOMEM; goto out_unreg; @@ -1261,11 +1295,9 @@ int mod_sysfs_setup(struct module *mod, out_unreg_param: module_param_sysfs_remove(mod); out_unreg_holders: - kobject_unregister(mod->holders_dir); + kobject_put(mod->holders_dir); out_unreg: - kobject_del(&mod->mkobj.kobj); kobject_put(&mod->mkobj.kobj); -out: return err; } #endif @@ -1274,9 +1306,20 @@ static void mod_kobject_remove(struct module *mod) { module_remove_modinfo_attrs(mod); module_param_sysfs_remove(mod); - kobject_unregister(mod->mkobj.drivers_dir); - kobject_unregister(mod->holders_dir); - kobject_unregister(&mod->mkobj.kobj); + kobject_put(mod->mkobj.drivers_dir); + kobject_put(mod->holders_dir); + kobject_put(&mod->mkobj.kobj); +} + +/* + * link the module with the whole machine is stopped with interrupts off + * - this defends against kallsyms not taking locks + */ +static int __link_module(void *_mod) +{ + struct module *mod = _mod; + list_add(&mod->list, &modules); + return 0; } /* @@ -1328,7 +1371,7 @@ void *__symbol_get(const char *symbol) preempt_disable(); value = __find_symbol(symbol, &owner, &crc, 1); - if (value && !strong_try_module_get(owner)) + if (value && strong_try_module_get(owner) != 0) value = 0; preempt_enable(); @@ -1369,7 +1412,7 @@ dup: return ret; } -/* Change all symbols so that sh_value encodes the pointer directly. */ +/* Change all symbols so that st_value encodes the pointer directly. */ static int simplify_symbols(Elf_Shdr *sechdrs, unsigned int symindex, const char *strtab, @@ -1882,16 +1925,16 @@ static struct module *load_module(void __user *umod, /* Now we've moved module, initialize linked lists, etc. */ module_unload_init(mod); - /* Initialize kobject, so we can reference it. */ + /* add kobject, so we can reference it. */ err = mod_sysfs_init(mod); if (err) - goto cleanup; + goto free_unload; /* Set up license info based on the info section */ set_license(mod, get_modinfo(sechdrs, infoindex, "license")); if (strcmp(mod->name, "ndiswrapper") == 0) - add_taint(TAINT_PROPRIETARY_MODULE); + add_taint_module(mod, TAINT_PROPRIETARY_MODULE); if (strcmp(mod->name, "driverloader") == 0) add_taint_module(mod, TAINT_PROPRIETARY_MODULE); @@ -2021,6 +2064,11 @@ static struct module *load_module(void __user *umod, printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", mod->name); + /* Now sew it into the lists so we can get lockdep and oops + * info during argument parsing. Noone should access us, since + * strong_try_module_get() will fail. */ + stop_machine_run(__link_module, mod, NR_CPUS); + /* Size of section 0 is 0, so this works well if no params */ err = parse_args(mod->name, mod->args, (struct kernel_param *) @@ -2029,7 +2077,7 @@ static struct module *load_module(void __user *umod, / sizeof(struct kernel_param), NULL); if (err < 0) - goto arch_cleanup; + goto unlink; err = mod_sysfs_setup(mod, (struct kernel_param *) @@ -2037,7 +2085,7 @@ static struct module *load_module(void __user *umod, sechdrs[setupindex].sh_size / sizeof(struct kernel_param)); if (err < 0) - goto arch_cleanup; + goto unlink; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); @@ -2052,9 +2100,13 @@ static struct module *load_module(void __user *umod, /* Done! */ return mod; - arch_cleanup: + unlink: + stop_machine_run(__unlink_module, mod, NR_CPUS); module_arch_cleanup(mod); cleanup: + kobject_del(&mod->mkobj.kobj); + kobject_put(&mod->mkobj.kobj); + free_unload: module_unload_free(mod); module_free(mod, mod->module_init); free_core: @@ -2074,17 +2126,6 @@ static struct module *load_module(void __user *umod, goto free_hdr; } -/* - * link the module with the whole machine is stopped with interrupts off - * - this defends against kallsyms not taking locks - */ -static int __link_module(void *_mod) -{ - struct module *mod = _mod; - list_add(&mod->list, &modules); - return 0; -} - /* This is where the real work happens */ asmlinkage long sys_init_module(void __user *umod, @@ -2109,10 +2150,6 @@ sys_init_module(void __user *umod, return PTR_ERR(mod); } - /* Now sew it into the lists. They won't access us, since - strong_try_module_get() will fail. */ - stop_machine_run(__link_module, mod, NR_CPUS); - /* Drop lock so they can recurse */ mutex_unlock(&module_mutex); @@ -2131,6 +2168,7 @@ sys_init_module(void __user *umod, mutex_lock(&module_mutex); free_module(mod); mutex_unlock(&module_mutex); + wake_up(&module_wq); return ret; } @@ -2145,6 +2183,7 @@ sys_init_module(void __user *umod, mod->init_size = 0; mod->init_text_size = 0; mutex_unlock(&module_mutex); + wake_up(&module_wq); return 0; } @@ -2209,32 +2248,41 @@ static const char *get_ksymbol(struct module *mod, return mod->strtab + mod->symtab[best].st_name; } -/* For kallsyms to ask for address resolution. NULL means not found. - We don't lock, as this is used for oops resolution and races are a - lesser concern. */ -const char *module_address_lookup(unsigned long addr, - unsigned long *size, - unsigned long *offset, - char **modname) +/* For kallsyms to ask for address resolution. NULL means not found. Careful + * not to lock to avoid deadlock on oopses, simply disable preemption. */ +char *module_address_lookup(unsigned long addr, + unsigned long *size, + unsigned long *offset, + char **modname, + char *namebuf) { struct module *mod; + const char *ret = NULL; + preempt_disable(); list_for_each_entry(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { if (modname) *modname = mod->name; - return get_ksymbol(mod, addr, size, offset); + ret = get_ksymbol(mod, addr, size, offset); + break; } } - return NULL; + /* Make a copy in here where it's safe */ + if (ret) { + strncpy(namebuf, ret, KSYM_NAME_LEN - 1); + ret = namebuf; + } + preempt_enable(); + return (char *)ret; } int lookup_module_symbol_name(unsigned long addr, char *symname) { struct module *mod; - mutex_lock(&module_mutex); + preempt_disable(); list_for_each_entry(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { @@ -2244,12 +2292,12 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) if (!sym) goto out; strlcpy(symname, sym, KSYM_NAME_LEN); - mutex_unlock(&module_mutex); + preempt_enable(); return 0; } } out: - mutex_unlock(&module_mutex); + preempt_enable(); return -ERANGE; } @@ -2258,7 +2306,7 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, { struct module *mod; - mutex_lock(&module_mutex); + preempt_disable(); list_for_each_entry(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { @@ -2271,12 +2319,12 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, strlcpy(modname, mod->name, MODULE_NAME_LEN); if (name) strlcpy(name, sym, KSYM_NAME_LEN); - mutex_unlock(&module_mutex); + preempt_enable(); return 0; } } out: - mutex_unlock(&module_mutex); + preempt_enable(); return -ERANGE; } @@ -2285,7 +2333,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, { struct module *mod; - mutex_lock(&module_mutex); + preempt_disable(); list_for_each_entry(mod, &modules, list) { if (symnum < mod->num_symtab) { *value = mod->symtab[symnum].st_value; @@ -2294,12 +2342,12 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, KSYM_NAME_LEN); strlcpy(module_name, mod->name, MODULE_NAME_LEN); *exported = is_exported(name, mod); - mutex_unlock(&module_mutex); + preempt_enable(); return 0; } symnum -= mod->num_symtab; } - mutex_unlock(&module_mutex); + preempt_enable(); return -ERANGE; } @@ -2322,6 +2370,7 @@ unsigned long module_kallsyms_lookup_name(const char *name) unsigned long ret = 0; /* Don't lock: we're in enough trouble already. */ + preempt_disable(); if ((colon = strchr(name, ':')) != NULL) { *colon = '\0'; if ((mod = find_module(name)) != NULL) @@ -2332,6 +2381,7 @@ unsigned long module_kallsyms_lookup_name(const char *name) if ((ret = mod_find_symname(mod, name)) != 0) break; } + preempt_enable(); return ret; } #endif /* CONFIG_KALLSYMS */ @@ -2353,21 +2403,30 @@ static void m_stop(struct seq_file *m, void *p) mutex_unlock(&module_mutex); } -static char *taint_flags(unsigned int taints, char *buf) +static char *module_flags(struct module *mod, char *buf) { int bx = 0; - if (taints) { + if (mod->taints || + mod->state == MODULE_STATE_GOING || + mod->state == MODULE_STATE_COMING) { buf[bx++] = '('; - if (taints & TAINT_PROPRIETARY_MODULE) + if (mod->taints & TAINT_PROPRIETARY_MODULE) buf[bx++] = 'P'; - if (taints & TAINT_FORCED_MODULE) + if (mod->taints & TAINT_FORCED_MODULE) buf[bx++] = 'F'; /* * TAINT_FORCED_RMMOD: could be added. * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't * apply to modules. */ + + /* Show a - for module-is-being-unloaded */ + if (mod->state == MODULE_STATE_GOING) + buf[bx++] = '-'; + /* Show a + for module-is-being-loaded */ + if (mod->state == MODULE_STATE_COMING) + buf[bx++] = '+'; buf[bx++] = ')'; } buf[bx] = '\0'; @@ -2394,7 +2453,7 @@ static int m_show(struct seq_file *m, void *p) /* Taints info */ if (mod->taints) - seq_printf(m, " %s", taint_flags(mod->taints, buf)); + seq_printf(m, " %s", module_flags(mod, buf)); seq_printf(m, "\n"); return 0; @@ -2489,97 +2548,12 @@ void print_modules(void) printk("Modules linked in:"); list_for_each_entry(mod, &modules, list) - printk(" %s%s", mod->name, taint_flags(mod->taints, buf)); + printk(" %s%s", mod->name, module_flags(mod, buf)); + if (last_unloaded_module[0]) + printk(" [last unloaded: %s]", last_unloaded_module); printk("\n"); } -#ifdef CONFIG_SYSFS -static char *make_driver_name(struct device_driver *drv) -{ - char *driver_name; - - driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2, - GFP_KERNEL); - if (!driver_name) - return NULL; - - sprintf(driver_name, "%s:%s", drv->bus->name, drv->name); - return driver_name; -} - -static void module_create_drivers_dir(struct module_kobject *mk) -{ - if (!mk || mk->drivers_dir) - return; - - mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers"); -} - -void module_add_driver(struct module *mod, struct device_driver *drv) -{ - char *driver_name; - int no_warn; - struct module_kobject *mk = NULL; - - if (!drv) - return; - - if (mod) - mk = &mod->mkobj; - else if (drv->mod_name) { - struct kobject *mkobj; - - /* Lookup built-in module entry in /sys/modules */ - mkobj = kset_find_obj(&module_subsys, drv->mod_name); - if (mkobj) { - mk = container_of(mkobj, struct module_kobject, kobj); - /* remember our module structure */ - drv->mkobj = mk; - /* kset_find_obj took a reference */ - kobject_put(mkobj); - } - } - - if (!mk) - return; - - /* Don't check return codes; these calls are idempotent */ - no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module"); - driver_name = make_driver_name(drv); - if (driver_name) { - module_create_drivers_dir(mk); - no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj, - driver_name); - kfree(driver_name); - } -} -EXPORT_SYMBOL(module_add_driver); - -void module_remove_driver(struct device_driver *drv) -{ - struct module_kobject *mk = NULL; - char *driver_name; - - if (!drv) - return; - - sysfs_remove_link(&drv->kobj, "module"); - - if (drv->owner) - mk = &drv->owner->mkobj; - else if (drv->mkobj) - mk = drv->mkobj; - if (mk && mk->drivers_dir) { - driver_name = make_driver_name(drv); - if (driver_name) { - sysfs_remove_link(mk->drivers_dir, driver_name); - kfree(driver_name); - } - } -} -EXPORT_SYMBOL(module_remove_driver); -#endif - #ifdef CONFIG_MODVERSIONS /* Generate the signature for struct module here, too, for modversions. */ void struct_module(struct module *mod) { return; } |